This study was designed to evaluate the feasibility of performing aorto-coronary vein bypasses in patients dying with large, acute myocardial infarcts. The postmortem luminal diameters of distal segments of coronary arteries were measured in 40 such hearts. The measurements were taken in the distal right coronary artery, middle third of left anterior descending artery, and marginal branch of the left circumflex coronary artery (common sites for aorto-coronary vein bypass). In addition, five other alternate sites were similarly evaluated. Ninety-six percent (38) of all potential anastomotic sites were patent. The common sites of aorto-coronary vein bypass were patent in 93% (37). The luminal diameter of the artery supplying the fatal myocardial infarction, at the site of possible aorto-coronary vein bypass, was patent and suitable for bypass grafts in 95% (38) of 40 hearts studied.